I was looking for some interesting ideas for using lithium polymer cells and stumbled across this diy flashlight. (It’s on geocities, so hit the cache.) Flashlights aren’t usually that interesting, but this one uses a pair of li-poly cells and a PWM signal generated by a pic controller to regulate the power to the lamp using a IRL1404 MOSFET. It still requires an external li-poly charger, but looks like a nice project to get into li-poly and PWM applications.